unexpected end of upload Stream

[pholder]

Hello folks,

I'm using BMP 2.0 beta -8 and I am encountering a strange behaviour.
My goal is to simulate a modem Speed connection in a Selenium Remote enviroment, so I'm using the REST-API. To recall the error, the following steps are necessary:

create a new proxy-Instance with:
HttpPost createProxy = new HttpPost("http://192.168.1.160:8080/proxy");

clear out the Cache with:
HttpDelete httpDeleteProxyCache = new HttpDelete("http://192.168.1.160:8080/proxy/9999/dns/cache");

then limit the connection-speed with these commands:
List params = new ArrayList(4);
params.add(new BasicNameValuePair("enabled", "true"));
params.add(new BasicNameValuePair("downstreamKbps", "56"));
params.add(new BasicNameValuePair("upstreamKbps", "56"));

HttpPut httpPutLimiter = new HttpPut("http://192.168.1.160:8080/proxy/9999/limit");

httpPutLimiter.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));
new DefaultHttpClient().execute(httpPutLimiter);

I can see in my Browser (Firefox 21) that the speed is indeed slow and surfing the Internet works fine, but if I try to upload a file of around 43kb on the following site:

http://cgi-lib.berkeley.edu/ex/fup.html

I get an Error that something went wrong. This seems to apear when ever I try to upload larger files, however it does not appear with smaller files.
The console of BMP give me the following output:

INFO 05/24 09:51:55 n.l.b.p.Main - Starting BrowserMob Proxy version 2.0
-beta-8
INFO 05/24 09:51:55 o.e.j.u.log - jetty-7.3.0.v20110203
INFO 05/24 09:51:55 o.e.j.u.log - started o.e.j.s.ServletContextHandler
{/,null}
INFO 05/24 09:51:56 o.e.j.u.log - Started SelectChannelConnector@0.0.0.
0:8080
INFO 05/24 09:52:00 n.l.b.p.j.h.HttpSer~ - Version Jetty/5.1.x
INFO 05/24 09:52:00 n.l.b.p.j.u.Contain~ - Started HttpContext[/,/]
INFO 05/24 09:52:00 n.l.b.p.j.h.SocketL~ - Started SocketListener on 0.0.0.0:999
9
INFO 05/24 09:52:00 n.l.b.p.j.u.Contain~ - Started net.lightbody.bmp.proxy.jetty
.jetty.Server@41480ec1
INFO 05/24 09:53:06 n.l.b.p.h.BrowserMo~ - java.net.SocketException: Software ca
used connection abort: socket write error when requesting http://cgi-lib.berkele
y.edu/ex/fup.cgi
WARN 05/24 09:53:06 n.l.b.p.j.h.HttpCon~ - POST http://cgi-lib.berkeley.edu/ex/f
up.cgi HTTP/1.1 HttpException(400,Bad Request,Missing Content)

Can this be a problem with the StreamManager from BMP?